NavIC System and Applications - Status & Update - Akhileshwar Reddy Satellite Navigation Programme Office ISRO Headquarters 11 Jan 2022 - UNOOSA

NavIC System and Applications –
 Status & Update
 Akhileshwar Reddy
 Satellite Navigation Programme Office
 ISRO Headquarters
 11 Jan 2022

 ISRO 1

NavIC Architecture
• NavIC stands for ‘Navigation with Indian Constellation’

• Regional navigation system of India

 * Civilian signal in L1 band is planned from upcoming NVS – 01 satellite

NavIC Constellation status
 Launch dates:
 55° E
 • IRNSS 1A : 01 Jul 2013 IRNSS-1I 83° E 111.75° E
 IRNSS-1A IRNSS-1C IRNSS-1D
 • IRNSS 1B : 04 Apr 2014
 • IRNSS 1C : 16 Oct 2014
 • IRNSS 1D : 28 Mar 2015
 • IRNSS 1E : 20 Jan 2016 IRNSS-1B IRNSS-1E

 • IRNSS 1F : 10 Mar 2016
 • IRNSS 1G : 28 Apr 2016
 • IRNSS 1I : 12 Apr 2018

 All launches using Polar Satellite
 Launch Vehicle (PSLV) from Satish • GSO satellites (shown in blue) are with ~4 inclination
 • GSO satellites (shown in orange) are with 29 inclination
 Dhawan Space Centre (SDSC) at
 Sriharikota IRNSS 1A and 1E are providing NavIC based safety of life alerts

NavIC Coverage Area

 NavIC being a regional
constellation, provides its services
 to Indian mainland and 1500km
 beyond the boundary

 Accuracy (2σ, 3D)
  Position < 20 m Indian mainland and
  Timing < 50 ns 1500 km beyond

NavIC Documentation

NavIC Documentation on ISRO website:

• NavIC SIS ICD for the L5, S SPS signal

• Quarterly performance reports of
 NavIC signals in the coverage region

• SIS ICD for the new L1 civilian signal is
 going to be available soon

 https://www.isro.gov.in/irnss-programme

NavIC System Updates
 NavIC System Advisory is planned to be launched shortly
 NVS-01/02/03/04/05 planned over the next few years beginning 2022
 Continuity of service with following new features:
 o Introduction of service in L1 band
 o Indigenous novel ranging code in L1 band
 o Inhouse developed space-grade atomic clocks
 Centre Frequency Band
 Frequency Band
 (MHz) (MHz)
 L5-band 1176.45 1164.45 – 1188.45
 S-band 2492.028 2483.5 – 2500
 L1-band 1575.42 1563.42 – 1587.42

NavIC L1 signal

 Interoperable with other modernised GNSS signals

 Modulation: NavIC SBOC(6,1,1/11)
  Power spectral density: MBOC (6,1,1/11)

 Channel coding: NavIC BCH and LDPC

 PRN code: Interleaved Z4-Linear Codes (IZ4)

 Data structure: Similar skeleton to GPS L1C

NavIC L1 signal - Modulation

 Implementation of MBOC (6,1,1/11)

 TMBOC: time multiplexed BOC
 CBOC: composite BOC
 QMBOC: quadrature multiplexed BOC
 SBOC: synthesised BOC

 SBOC implementation:
  Data & Pilot will have BOC(1,1) and BOC(6,1)
  = , ( ) − , ( ൯ + , + , = + 
  Coefficients are adjusted to make MBOC (6,1,1/11) PSD

NavIC L1 signal - PRN Codes

 NavIC L1 signal shall use a family of Interleaved Z4 – Linear (IZ4) PRN spreading
 codes implemented using coupled shift registers

 The PRN code length is 10230 chips with code period of 10 ms in both data and
 pilot channels. The pilot channel has a secondary overlay code of length 1800 and a
 period of 18 s. Pilot and data signals are orthogonal.

 The IZ4 family of spreading codes are found to provide better or on-par
 performance compared to the PRN code families used by GPS and BeiDou in the L1
 band

 The resources required for implementing the code generator are of the same order
 as Weil codes

NavIC L1 signal - Data Structure

 Data structure of NavIC L1
 signal is similar to GPS L1C 1800 symbols (at 100 symbols/sec)

 The master frame is 18 sec in
 Subframe-1 (52 symbols) Subframe-2 and Subframe-3 (1748 symbols)
 duration with 3 sub-frames
 Block Interleaving
 Total 1800 symbols: 46 x 38 (columns x rows)
 Subframe-2 and Subframe-3 (1748 symbols)
  SF-1: 52 symbols
  SF-2: 1200 symbols
 Subframe-1 (52 symbols) Subframe-2 (1200 symbols) Subframe-3 (548 symbols)
  SF-3: 548 symbols
 BCH Coding LDPC Coding LDPC Coding
 Symbol rate: 100 sps
 Error Correction Coding Subframe-1 (9 bits TOI) Subframe-2 (600 bits) Subframe-3 (274 bits)

 scheme
 Primary Parameters CRC Secondary Parameters CRC
  BCH(52,9) for SF-1 (576 bits) (24 bits) (250 bits) (24 bits)
  Rate ½ LDPC for SF-2 & 3

NavIC Applications
 NMR Railways UAVs
 Atmosphere
 Monitoring

 VLTs Automobiles
 Power Grid
 2G-DAT Geodesy

 Precision Farming
Personal Trackers

 Mobile Phones

Off-the-shelf standalone GNSS chips

A few of the off-the-shelf chips for standalone GNSS (NavIC enabled):
 Telit, Allystar, Quectel, SkyTraQ, Broadcom, U-TraQ

NavIC based commercial vehicle safety

• Ministry of Road Transport and Highway (MoRTH) has mandated use of AIS-140
 compliant NavIC enabled vehicle tracking systems in all public and commercial vehicles
 in India.
• ISRO has supported Automotive Research Association of India (ARAI), International
 Centre for Automotive Technology (ICAT) to test and certify the NavIC enabled AIS-140
 compliant vehicle tracking devices.
• ARAI & ICAT have certified products from >100 companies.
 https://cms.araiindia.com/MediaFiles/List%20AIS%20140%20as%20on%2024th%20Feb%202021_11582.pdf
 https://icat.in/storage/app/public/uploads/certificate_form_1564983033.pdf

• Several tens of thousand vehicles are now plying the roads equipped with these devices.

NavIC based commercial vehicle safety

 NavIC
 Typical architecture

 Vehicle LAN /
 Target internet
 info.

 User control room

 Police
 control room

 Police
 patrol
 GSM/GPRS

NavIC based Safety-of-Life Alerts
 Introduced to provide safety-of-life Short Messaging Services – NavIC Messaging
 alerts for fishermen when they Services (One Way)
 undertake deep sea fishing with no
 other means of receiving alerts.
 INCOIS broadcasts the messages related User
 Feedback
 Navigation Navigation
 to high wave, cyclone, and tsunami. software @
 ISRO
 centre
 Satellites
 for
 One-way broadcasting system. messaging

 Receiver technology transferred to
 Indian industries.
 Field Trials conducted. Feedback
 Satellite
 received Positioning
 receiver
 uplink

NavIC based Safety-of-Life Alerts
 DAT-SG: Integrated Distress Alert Transmitter and NavIC
 NavIC messaging service messaging Service
 provide acknowledgement of (2-Way messaging system)
 distress signals generated by
 fishermen.
 Prototype terminals have been
 successfully tested
 Hub/server has been configured
 at ISRO for final commissioning.
 Trans-receiver technology
 transferred to Indian industries.

NavIC based Safety-of-Life Alerts Documentation

NavIC Messaging Documentation on
ISRO website:

• SIS ICD for the NavIC messaging
 service used by INCOIS

• SIS ICD for the second generation
 Distress Alert Transmitter (DAT-SG)

 https://www.isro.gov.in/irnss-programme

NavIC Enabled Mobile Phone SoC

800 Series 700 Series 600 Series 400 Series
(High end) (Semi- High end) (Mid-Range) (Low-Range)
 SD 888 SD 768G SD 690 SD 460
 SD 870 SD 765G SD 662
 SD 865+ SD 765
 SD 865 SD 750G
 SD 720G

Mediatek Dimensity: 1200, 1000c, 700

Huawei kirin: 9000, 990 5G

Samsung Exynos: 980

NavIC Enabled Mobile Phones

Sl. Mobile Cost range
No. (INR)
 1 Poco m2 pro 10K – 20K
 2 Redmi Note 9 Pro
 3 Redmi Note 9 Pro max
 4 Real me 6 Pro
 5 Mi 10i 20K – 50K
 6 Vivo v20
 7 One Plus Nord
 8 Vivo V20 pro
 9 Mi 10T
 10 Mi 10T pro
 11 Real Me X50 pro 5G*
 12 Mi 10
 13 Huawei P40 > 50K
 14 Asus Zenphone 7 pro
 15 Huawei p40 pro
 16 Huawei Mate 40 Pro

NavIC in 3GPP

• NavIC has become a part of the latest specifications of 3GPP for Assisted- Global
 Navigation Satellite System (A-GNSS).
• Incorporation of NavIC into 3GPP Release-16 standards will ensure common
 denominator performance of NavIC assistance among various telecom service
 providers.
• Also, mobile handsets with NavIC capability will be able to obtain the benefits of
 Assisted-GNSS.

NavIC in Standards
 International Maritime Organisation (IMO) has recognized NavIC as a
 component of the worldwide radio navigation system (WWRNS).
 Activities are underway for incorporation of NavIC in the appropriate IEC
 standards – IEC TC-80.
 NavIC has been incorporated in the latest National Marine Electronics
 Association (NMEA) 0183 standard.
 NavIC L5 has been included in the latest release of Radio Technical
 Commission for Maritime Services (RTCM) 10403.3 standard.
 TED-14 committee under BIS has recently released standards for
 Agricultural Drones which includes NavIC for position computation.

 ISRO 21

NavIC RTK Proof of Concept Development
 Base and Rover Antenna

 NavIC Base and Rover RTK Rx

• Carried out at Space Applications Center, ISRO
• Two receiver configuration, base receiver and rover
 receiver.
• Real-time data link between base and rover receivers
 using UHF Radio modem/GPRS Modem

 ISRO 22

NavIC RTK PoC results

 ISRO 23

Thank You

 ISRO 24

Comparative Performance of L1 PRN codes

 ISRO 25